ChemInform Abstract: Conformations and Thermodynamic Properties of Sulfur Homocycles. Part 1. The S5, S6, S7, and S8 Molecules.

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Cyclization and rearrangements of diterpenoids. IX. Isomerization of (1R,2S,7S,10S,11R,12S,13S)-2,6,6,10,12-pentamethylpentacyclo[10.2.1.01,10.02,7.011,13]pentadecane by fluorosulfonic acid

It has been shown that the opening of the cyclopropane ring in (1R, 2S, 7S, 10S, 11R, 12S, 13S)-2,6,6,10,12-pentamethylpentacyclo[10.2.1.0^1,10.0^2,7.0^11,13]pentadecane takes place under the action of fluorosulfonic acid at all three carbon-carbon bonds, but at low temperatures the main isomerization product is (1R, 2S, 7S, 10S, 12S, 13S)-2,6,6,10,12-pentamethyltetracyclo[10.2.1.0^1,10.0^2,7]pentadecan-13-ol, and at the ordinary temperature the main products are (1R, 2S, 7S, 11S, 12R, 13R)-2,6,6,11,13-pentamethyltetracyclo[10.2.1.0^1,10.0^2,7]pentadeca-9-ene and (1S, 2R, 11S, 12R, 15R)-2,7,7,11,15-pentamethyltetracyclo[10.2.1.0^2,11.0^3,8]pentadeca-3(8)-ene.     

Cyclization and rearrangements of diterpenoids. VIII. Products of dehydration of (1S,2S,7S,10R,11S,12S)-2,6,6,10,12-pentamethyltetracyclo[10.2.1.01,10.02,7]-pentadecan-11-ol by phosphorus oxychloride

On the dehydration of (1S, 2S, 7S, 10R, 11S, 12S)-2,6,6,10,12-pentamethyltetracyclo[10.2.1.0^1,10.0^2,7]pentadecan-11-ol by phosphorus oxychloride in pyridine a mixture of three hydrocarbons is formed: the known (1R, 2S, 7S, 10S, 11R, 12S, 13S)-2,6,6,10,12-pentamethyltetracyclo[10.2.1.0^1,10.0^2,7.0^11,13]pentadecane and the previously undescribed (1R, 2S, 7S, 10S, 11S)-2,6,6,10,12-pentamethyltetra-cyclo[9.2.2.0^1,10.0^2,7]pentadeca-12-ene and (1R, 2S, 7S, 10S, 11S)-2,6,6,10-tetramethyl-12-methylenetetracyclo[9.2.2.0^1,10.0^2,7]pentadecane, based on a new carbon skeleton.     

Cyclization and rearrangement of diterpenoids. VI. Products of dehydration of (1R,2S,7S,10S,12S,13S)-2,6,6,10,12-pentamethyltetracyclo[10.2.1.01,10.02,7]pentadecan-13-ol by phosphorus oxychloride

It has been established that on the dehydration of (1R,2S,7S,10S,12S,13S)-2,6,6,10,12-pentamethyltetracyclo[10.2.1.0^1,10.0^2,7]pentadecan-13-ol with phosphorus oxychloride in pyridine a mixture of six substances is formed, from which three previously undescribed hydrocarbons have been isolated and identified: (1R,2S,7S,10S,11R,12S,13S)-2,6,6,10,12-pentamethylpentacyclo[10.2.1.0^1,10.0^2,7.-0^11,13]pentadecane, (1R,2S,7S,10S,12R)-2,6,6,10,13-pentamethyltetracyclo[10.2.1.0^1,10.0^2,7]pentadec-13(14)-ene, and (1R,2S,7S,10S,12R)-2,6,6,10-tetramethyltetracyclo[10.2.1.0^1,10.0^2,7]pentadec-13(16)-ene, these being based on two new carbon skeletons.Institute of Chemistry, Institute of Applied Physics, MSSR Academy of Sciences, Kishinev. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 203–211, March–April, 1988.     

Synthesis of 6S, 7S-anhydro-serricornine.

Diastereoselective and enantioselective reduction of the β-ketoester $\text{3}$ by yeast to $\text{4}$ provided the chiral starting material for a synthesis of 4RS,6S,7S-serricornine, having the same configuration as the natural product. This material was converted into optically active and diastereomerically pure 6S,7S-anhydro-serricornine ($\text{2}$).