A Stereoselective Synthesis of the Carbon Backbone of Phoslactomycin B

作者：Raghavan Sadagopan; Patel Javed Sardar

来源：European Journal of Organic Chemistry, 2017, 2017(20): 2981-2997.

DOI：10.1002/ejoc.201700379

<jats:p>A convergent synthesis of the entire carbon framework of phoslactomycin B is disclosed. An initial route aimed to create the C‐8 tetrasubstituted stereocentre through regioselective intermolecular coupling between an internal alkyne and an allyl silyl ether, adopting Trost's protocol, followed by [2,3] sigmatropic rearrangement. But this was not successful. In a second approach, a propargylic sulfide was rearranged to give an unsaturated ketone. This was then treated with lithio acetonitrile to create the C‐8 stereocentre selectively. The C‐4 and C‐5 stereocentres were introduced by a non‐Evans <jats:italic>syn</jats:italic>‐aldol reaction using Crimmins's protocol. The C‐9 and C‐11 carbinol centres were created by asymmetric transfer hydrogenation. The (<jats:italic>Z</jats:italic>,<jats:italic>Z</jats:italic>)‐diene moiety was introduced by partial reduction of a diyne following Hansen's modification of the Boland reduction reaction.</jats:p>

• 出版日期2017-5-26