Proposed biosynthetic intermediates of a marine monocyclic ether alkaloid, brevisamide (1) were synthesized for biosynthetic studies on the marine ladder-frame polyethers. The intermediates comprising a linear backbone with trans-olefin (2) and epoxide (3) functionality were synthesized via a Suzuki-Miyaura cross coupling reaction and a Katsuki Sharpless asymmetric epoxidation reaction. In protic solvents, 3 was unstable and readily cyclized to an unnatural 5-membered ether ring compound (4).
Proposed biosynthetic intermediates of a marine monocyclic ether alkaloid, brevisamide (1) were synthesized for biosynthetic studies on the marine ladder-frame polyethers. The intermediates comprising a linear backbone with trans-olefin (2) and epoxide (3) functionality were synthesized via a Suzuki-Miyaura cross coupling reaction and a Katsuki Sharpless asymmetric epoxidation reaction. In protic solvents, 3 was unstable and readily cyclized to an unnatural 5-membered ether ring compound (4).
The first examples of highly selective deprotection of silyl ethers by DIBALH are reported. Its selectivity enabled us to remove a primary TBS group and a primary TBDPS group in the presence of a secondary TES group. (C) 2010 Elsevier Ltd. All rights reserved.