Total synthesis of N-malayamycin A and related bicyclic purine and pyrimidine nucleosides.

Methods are described for the total synthesis of bicyclic perhydrofuropyran nucleosides as N-analogues of the naturally occurring malayamycin A. Formation of the N-nucleosides relied on the activation of thioglycosides, proceeding via sulfonium intermediates. Ring closure metathesis was used in two approaches to build the bicyclic dioxa heterocycle.

Total synthesis and structural confirmation of malayamycin A: a novel bicyclic C-nucleoside from Streptomyces malaysiensis.

[reaction: see text] The stereocontrolled synthesis of malayamycin A, a novel naturally occurring bicyclic C-nucleoside of the perhydrofuropyran type, is described.