Asymmetric synthesis polypropionate fragments

The sunuhaneous double Diels-Alder addition of l,l-bis(3,5-dimethylfur-2-yl)ethane (8) with a biS dienophile such as diethyl ( , )-4-oxohepta-2,5-diene-1,7-dioate was proposed as new, asymmetric synthesis of long-chain polypropionate fragments and analogues <96TL4149>. 

Today, effective asymmetric catalysis is available for HDA, and it has been applied in the synthesis of polypropionate fragments of natural products. An example is shown is Scheme 10.51. ... 

SCHEME 10.51. Application of asymmetric hetero-Diels-Alder reaction in synthesis of polypropionate fragments. 

Huang XG, Craita C, Vogel P. Palladium-catalyzed conversion of (3,7-unsaturated silyl suliinates into (E)-alkenes asymmetric synthesis of polypropionate fragments. J. Org. Chem. 2004 69(12) 4272 275. 

A synthesis of both the polypropionate and spiroacetal fragments of rutamycin B have been described by Panek and Jain [65]. The majority of stereocenters were introduced via asymmetric allylation and crotylation reactions however, an aldol... 

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