Dihydro-deoxyarteannuin

Sy, L. K. Brown, G. D. Deoxyarteannuin-B, dihydro-deoxyarteannuin-B and tans-5-hydroxy- 2-isopropenyl-5-methylhex-3-en-l-ol from Artemisia anuua. Phytochemistry, 2001, 58(8) 1159-1166. 

Dudley and co-workers used a relay ring-closing metathesis strategy in the synthesis of (+)-dihydro-e/ /-deoxyarteannuin B, a key biogenic... 

The key step in the total synthesis of dihydro-epi-deoxyarteannuin B (73) reported by Dudley et al. involved metathesis closure of the hindered alkene in 72 [23]. This was first attempted, unsuccessfully, with the parent diene 72 (Scheme 9.17). CM, presumably with benzyUdene fragments from the initiator, was observed. It is likely that obligate loading of the metal to either of the hindered alkene carbons ( or A) in 72 was simply too difficult. This problem was nicely and efficiently solved through the RRCM of analog 74. Here, the relay event provided for insertion of the metal onto carbon A and the subsequent RCM. 

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