Three analogues of 1 alpha,25-dihydroxyvitamin D-3 (calcitriol), featuring a transfused decalin C, D-core with local S-2-symmetry, and possessing identical side-chain and seco-B,A-ring structures, have been synthesized starting from readily available (4aR, 8aS)octahydronaphthalene-1,5-dione(7). The very short sequences involve the simultaneous introduction of the side-chain and seco-B, A-ring fragments via Suzuki and Sonogashira coupling reactions. The analogues are devoid of relevant biological activity
