Routes involving Cyclopentane Ring Synthesis

Reagents i, Aq. citrate, buffer ii, KOH iii, NaI0.i-0s04 iv, Zn HOAc v, QH, COCH=PPha Vi, NaBHj 

NaBH4 vi, AcaO-CgHjN vii, (COCOj viii, McaCuLi ix, CF3CO3H ix, K2CO3 X, dihydropyran/H+ xi, LiBH xii, CHjNa xiii, Collins oxidation  

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Routes involving Cyclopentane Ring Synthesis.—Full details have appeared of a route to PGFi , due to Miyano et part of which was disclosed in preliminary form in 1969. The synthesis, which is outlined in Scheme 10, is... 

The copper(I) catalysed photo-cycloaddition reactions of the dienes (160) have been studied. This process provides an efficient route to the (2+2) cycloadducts (160a) in the ratios and yields shown under the appropriate structures. These adducts are key components in an approach to the synthesis of A -capnellene. Copper triflate controlled photocycloadditions have also been used as a key step in the synthesis of some cyclopentanes. The reaction involves the cyclization of the dienes (161) under the copper(I) controlled conditions into the adducts (162) and this is followed by thermal reactions that bring about rearrangement and ring opening. 

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