Synthesis of (+)-boronolide and (+)-deacetylboronolide using Pd-catalyzed carbonylation and lactonization

(+)-Boronolide and (+)-deacetylboronolide were synthesized using Pd-catalyzed CO insertion and lactonization as the key step. As to the C-13 NMR data of (+)-deacetylboronolide, the assignment at C-6 position should be revised.ArticleTETRAHEDRON LETTERS. 55(17):2822-2824 (2014)journal articl

SLOPT: Bandit Optimization Framework for Mutation-Based Fuzzing

Mutation-based fuzzing has become one of the most common vulnerability discovery solutions over the last decade. Fuzzing can be optimized when targeting specific programs, and given that, some studies have employed online optimization methods to do it automatically, i.e., tuning fuzzers for any given program in a program-agnostic manner. However, previous studies have neither fully explored mutation schemes suitable for online optimization methods, nor online optimization methods suitable for mutation schemes. In this study, we propose an optimization framework called SLOPT that encompasses both a bandit-friendly mutation scheme and mutation-scheme-friendly bandit algorithms. The advantage of SLOPT is that it can generally be incorporated into existing fuzzers, such as AFL and Honggfuzz. As a proof of concept, we implemented SLOPT-AFL++ by integrating SLOPT into AFL++ and showed that the program-agnostic optimization delivered by SLOPT enabled SLOPT-AFL++ to achieve higher code coverage than AFL++ in all of ten real-world FuzzBench programs. Moreover, we ran SLOPT-AFL++ against several real-world programs from OSS-Fuzz and successfully identified three previously unknown vulnerabilities, even though these programs have been fuzzed by AFL++ for a considerable number of CPU days on OSS-Fuzz.Comment: To appear in Proceedings of the 2022 Annual Computer Security Applications Conference (ACSAC '22

Synthesis of four diastereomers and structural revision of tetradenolide

Four diastereomers of tetradenolide, a cytotoxic α-pyrone isolated from Tetradenia riparia, were synthesized stereoselectively using the Z-selective Horner–Emmons reaction followed by acid catalyzed lactonization. Making comparison of the 1H and 13C NMR spectral data of the four diastereomers with those of the reported value of natural product did not lead to determine the relative stereochemistry of the natural tetradenolide. Thus detailed investigation of the spectral data of the related compounds led us to revise the structure of tetradenolide as deacetylboronolide.ArticleTETRAHEDRON LETTERS. 55(30):4189-4192 (2014)journal articl

RCABench: Open Benchmarking Platform for Root Cause Analysis

Fuzzing has contributed to automatically identifying bugs and vulnerabilities in the software testing field. Although it can efficiently generate crashing inputs, these inputs are usually analyzed manually. Several root cause analysis (RCA) techniques have been proposed to automatically analyze the root causes of crashes to mitigate this cost. However, outstanding challenges for realizing more elaborate RCA techniques remain unknown owing to the lack of extensive evaluation methods over existing techniques. With this problem in mind, we developed an end-to-end benchmarking platform, RCABench, that can evaluate RCA techniques for various targeted programs in a detailed and comprehensive manner. Our experiments with RCABench indicated that the evaluations in previous studies were not enough to fully support their claims. Moreover, this platform can be leveraged to evaluate emerging RCA techniques by comparing them with existing techniques.Comment: Accepted by NDSS 2023 Workshop on Binary Analysis Research (BAR); Best Paper Awar

Total synthesis of (+)-azimine via diastereoselective aminopalladation

The aminopalladation of amino allylic alcohol using Cl2Pd(MeCN)(2) in CH2Cl2 gave the 2,6-disubstituted piperidine with excellent diastereoselectivity. This compound was successfully converted into (+)-azimine (1) using cross-metathesis and Shiina macrolactonization.ArticleTETRAHEDRON. 69(39):8349-8352 (2013)journal articl

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus -- the "D-shuttle" project --

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter "D-shuttle" for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the background radiation level of other regions/countries

Total synthesis of (+)-azimine via diastereoselective aminopalladation

The aminopalladation of amino allylic alcohol using Cl2Pd(MeCN)(2) in CH2Cl2 gave the 2,6-disubstituted piperidine with excellent diastereoselectivity. This compound was successfully converted into (+)-azimine (1) using cross-metathesis and Shiina macrolactonization.ArticleTETRAHEDRON. 69(39):8349-8352 (2013)journal articl

Synthesis of (+)-boronolide and (+)-deacetylboronolide using Pd-catalyzed carbonylation and lactonization

(+)-Boronolide and (+)-deacetylboronolide were synthesized using Pd-catalyzed CO insertion and lactonization as the key step. As to the C-13 NMR data of (+)-deacetylboronolide, the assignment at C-6 position should be revised.ArticleTETRAHEDRON LETTERS. 55(17):2822-2824 (2014)journal articl