Polycyclic polyprenylated

Ciochina, R. and Grossman, R.B. (2006) Polycyclic polyprenylated acylphloroglucinols. Chemical Reviews, 106, 3963-3986. 

SnCl4 is also superior to 22 SnCl4, and is effective for the enantioselective cyclization of 2-(polyprenyl)phenol derivatives to give polycyclic terpenoids bearing a chroman skeleton.The synthetic utility of 26 SnCl4 is demonstrated by very... 

Superacid-catalysed intramolecular reactions of some dicationic electrophiles have been investigated.36 The positively charged centres migrate apart and this chemistry gives a new synthetic route to aza-polycyclic compounds. The polycyclic compound (26) can, for example, be formed from reaction of 2-phenyl-3-(l-hydroxy-2-phenyl-ethyl)quinoline (25) with CF3SO3H at 25 °C, loss of water and benzene being involved. Highly diastereoselective polycyclization of homo(polyprenyl)arenes [e.g. (27)... 

Phthalimide-N-sulfenyl chloride, 375 Phthaloylamino acids, 212 Phthaloyl-L-valine, 212 Phytuberin, 197 Phytyl chloride, 499, 500 Picrotoxinin, 265, 430 Pictei-Spengler cyclization, 308 Pinacol-typc reduction, 513 -Pinene, 346, 367 Piperidine acetate, 318 Piperidinium acetate, 375-376 Polonovski reaction, 484 Polyaminolactams, 378-379 Polycyclic phenols, 102 Polyene cyclization, 291-292 Polyethylene glycols, 360, 376 Polyketides, 302 Polyphosphate ester, 376-377 Polyprenylation, 499-500 Potassium-Ammonia, 273, 377 Potassium-t-Butylamine-18-Crown-6, 377-378... 

Benzophenone synthase (BPS) and biphenyl synthase (BIS) catalyze the formation of the same linear tetraketide from benzoyl-CoA and three molecules of malonyl-CoA. However, BPS cyclizes this intermediate via intramolecular C6-+C1 Claisen condensation, whereas BIS uses intramolecular C2— C7 aldol condensation. Benzophenone derivatives include polyprenylated polycyclic compounds with hi pharmaceutical potential. Biphenyl derivatives are the phytoalexins of the economically important Maloideae. 

SCHEME 9.38 Diastereoselective polycyclization of homo(polyprenyl)arene analogs bearing terminal sUoxyvinyl groups. 

Polyprenylated acylphloroglucinols, such as garsubeUin A (155) and hyperforin A (156), are bioactive molecules characterized by a polycyclic bridged system [32]. In 2005, Shibasaki et al. described a RCM-based total synthesis of ( )-garsubelhn A (Scheme 1.25) [33]. 

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