Study on the total synthesis of velbanamine: Chemoselective dioxygenation of alkenes with PIFA via a stop-and-flow strategy

Abstract

SummaryA “stop-and-flow” strategy was developed for the chemoselective dioxygenation of alkenes with a PIFA-initiated cyclization. This method is conceived for the desymmetrization of seco-diene, and a series of substituted 5-hydroxymethyl-γ-lactones were constructed after hydrolysis. This strategy also differentiates terminally substituted alkenes and constitutes a potentially novel synthetic approach for the efficient synthesis toward velbanamine.

α-Silyl Amides: Effective Bifunctional Lynchpins for Type I Anion Relay Chemistry

“…21 To this end, lynchpin 1 was combined with ( R )-(–)-benzyl glycidol ether 19 to furnish 20 in good yield with modest levels of diastereoselectivity. Following exposure to triflic anhydride, the known lactone 21 22 was isolated in 80% yield.…”

Managing Hazardous Reactions and Compounds in Process Chemistry

“…It can also be used to bring about cyclizations (Scheme 66). The use of a stop-and-flow method minimized side reaction (330).…”