Starting from (3R)-5-benzotriazolyl-3-phenylperhydropyrido[2,1-b][1,3]oxazole 9, the enantiodivergent syntheses of both enantiomers of the marine alkaloids haliclorensin 1 and isohaliclorensin 3 have been achieved. Our syntheses feature ring-expansion reactions for the formation of the aza-macrocycle ring system of 3 and sequential ring-expansion reactions (aza-Claisen rearrangement and Zip reaction) for the formation of the aza-macrocycle ring system of 1.

(2S,3S,7S)-3,7-Dimethylpentadecan-2-yl acetate (2) and its propionate analogue (3) are the main sex pheromones of all Neodiprion species and Diprion similes, respectively. Starting from (S)-malic acid and employing a highly chemo-, regio-, and stereoselective tandem ester reduction-epoxide formation-reductive epoxide-opening reaction protocol, an efficient total synthesis of (2S,3S,7S)-2 and -3 is reported herein.

A flexible non-amino acid-based formal asymmetric synthesis of naturally occurring antimicrobial (2R,3S)-2-aminotetradeca-5,7-dien-3-ol is reported. The method features a flexible and highly regioselective Grignard addition to (S)-malimide followed by a trans-diastereoselective reductive deoxygenation. The scope and limitations of the highly regio and diastereoselective reductive alkylation of malimides were defined. A remarkable protecting group effect on the regio and diastereoselective reductive alkylation of malimides was observed.

Diastereoselective a-amidoalkylation of N,O-acetal, derivated from controlled regio and diastereoselective reduction of (S)-N-(4-methoxybenzyl)-3-silyloxyglutarimide provided two diastereomeric 6-allyl-5-silyloxy-2-piperidinones in 76:24 selectivity. The transformation of the major diastereomer into a known advanced intermediate allowed the synthesis of (+)-febrifugine and (+)-isofebrifugine.

Selective and potent neurokinin substance P receptor antagonists (+)-L-733, 060 (1) and (+)-CP-99, 994 (2) have been synthesized starting from a new (3S)-piperidinol synthon derived from L-glutamic acid. The methods featured a C-2 regioselective reduction of glutarimide (9), Lewis acid-promoted Si to C-2 phenyl group migration of 10, and stereoselective reduction of acetylated oxime 19 as the key steps.