Total Synthesis of (+)-Cladospolide A

A stereoselective total synthesis of (+)-cladospolide A from D-ribose is described. Key features of the synthesis include olefin cross metathesis and Yamaguchi lactonization

2-Pyridylsulfinamides as effective catalysts in the asymmetric alkylation of aldehydes with diethylzinc

The enantioselective alkylation of aldehydes with diethylzinc is achieved in the presence of a chiral sulfinamide as optimal catalyst

An Expeditious Asymmetric Synthesis of the Polyketide Unit Present in HIV-Inhibitory Depsipeptides Aetheramide A and B

The enantioselective synthesis of the polyketide unit present in depsipeptides aetheramide A and B, which possess potent HIV-inhibitory activity, is accomplished from a chiral furyl carbinol

Total Synthesis of (+)-Seimatopolide A

Total synthesis of 10-membered lactone (+)-seimatopolide A is presented from furfural. Key reactions in the present strategy include the effective use of furan as a E-but-2-ene-1,4-dione surrogate, Nagao acetate aldol reaction, and Shiina lactonization

Total Synthesis of the Bis-silyl Ether of (+)-15-epi-Aetheramide A

Synthesis of the macrolactone depsipeptide aetheramide A was attempted by three different approaches. The first approach to form the macrolactone involving macrolactonization to form the C1-C21 bond and the second approach using a ring-closing metathesis (RCM) strategy to form the C10-C11 olefinic bond failed. The third approach starting from R-mandelic acid, involving the RCM reaction to install the C18-C19 ring junction, was successful in assembling the macrolactone

2-Pyridylsulfinamides as effective catalysts in the asymmetric alkylation of aldehydes with diethylzinc

Chiral 2-pyridylsulfinamides were shown to be effective catalysts in the alkylation of aryl and alkyl aldehydes with diethylzinc providing the corresponding alcohols in excellent enantioselectivity. Sulfinamide catalysts possessing solitary chirality at the sulfur center produced the product phenethyl alcohol in good enantioselectivity. Diastereomeric sulfinamides possessing chirality at the carbon-bearing nitrogen and at the sulfur of the sulfinamide increased the enantioselectivity of the product alcohols up to >99%. However, there is no effect of the match-mismatch pair of sulfinamide diastereomers on the outcome of the chiral induction of the product phenethyl alcohols. It was conclusively proved that chirality at the sulfur center is mandatory for obtaining good enantioselectivity in the reaction

Total Synthesis of the Bis-silyl Ether of (+)-15-<i>epi</i>-Aetheramide A

Synthesis of the macrolactone depsipeptide aetheramide A was attempted by three different approaches. The first approach to form the macrolactone involving macrolactonization to form the C1–C21 bond and the second approach using a ring-closing metathesis (RCM) strategy to form the C10–C11 olefinic bond failed. The third approach starting from <i>R</i>-mandelic acid, involving the RCM reaction to install the C18–C19 ring junction, was successful in assembling the macrolactone

Synthesis and evaluation of C-2-symmetric bis-sulfinamides as effective ligands in rhodium catalyzed addition of arylboronic acids to cycloalkenones

Synthesis of novel C-2-symmetric 1,2-1,3- and 1,4-bis-sulfinamides and their use as effective ligands in rhodium (I) catalyzed asymmetric conjugate addition of arylboronic acids to cyclohexenone and cyclopentenones is described. C-2-symmetry as well as chirality at the sulfur center in the ligand is crucial for the high enantioselectivity in the 1,4-addition reaction. It was also observed that the conjugate addition proceeded with good selectivity with Wilkinson's catalyst as the rhodium source. (C) 2016 Elsevier Ltd. All rights reserved