Endiandric Acids

Title: Endiandric Acids
Literature References: A group of novel polycyclic compounds isolated from leaves of the 'Dorrigo Plum', Endiandra introrsa C. T. White, Lauraceae, a large tree occurring in rain forests of Australia. Although they have a number of asymmetric centers, endiandric acids occur in nature in racemic rather than enantiomeric forms. This fact led to a proposed hypothesis for the "biogenesis" of these compounds in nature from achiral precursors by a series of non-enzymatic electrocyclizations called the "endiandric acid cascade". Isoln from E. introrsa leaves (obtained in 1958) and structure of endiandric acid A: W. M. Bandaranayake et al., Chem. Commun. 1980, 162. Postulated electrocyclic reactions, prediction of endiandric acid D as a natural product: eidem, ibid. 902. X-ray crystallographic structural elucidation of A and detailed report of isoln: eidem, Aust. J. Chem. 34, 1655 (1981). Isoln and structure of endiandric acid B: eidem, ibid. 35, 557 (1982); of C: eidem, ibid. 567. Stereocontrolled total synthesis of A and B, description of "endiandric acid cascade": K. C. Nicolaou et al., J. Am. Chem. Soc. 104, 5555 (1982). Stereocontrolled total synthesis of endiandric acids C-G: eidem, ibid. 5557. Synthesis of precursors and thermal studies: eidem, ibid. 5558, 5560.
Derivative Type: Endiandric Acid A
CAS Registry Number: 74591-03-0
CAS Name: (1R,1aR,2aR,5S,5aS,7aS,7bR,7cR)-rel-1a,2,2a,5,5a,7a,7b,7c-Octahydro-5-phenyl-1H-cyclobut[bc]acenaphthylene-1-acetic acid
Additional Names: 2-(6¢-phenyltetracyclo[5,4,2,03,13,010,12]trideca-4¢,8¢-dien-11¢-yl)acetic acid
Molecular Formula: C21H22O2
Molecular Weight: 306.40
Percent Composition: C 82.32%, H 7.24%, O 10.44%
Properties: Rods from aq ethanol, mp 147-149°. uv max (95% ethanol): 242, 255, 261, 268, 286 nm (log e 2.19, 2.36, 2.45, 2.32, 1.45). pKa 5.1, 5.0. Gives a yellow color with tetranitromethane.
Melting point: mp 147-149°
pKa: pKa 5.1, 5.0
Absorption maximum: uv max (95% ethanol): 242, 255, 261, 268, 286 nm (log e 2.19, 2.36, 2.45, 2.32, 1.45)
Derivative Type: Endiandric Acid B
CAS Registry Number: 76060-33-8
CAS Name: (2E)-rel-4-[(1R,1aR,2aR,5S,5aS,7aS,7bR,7cR)-1a,2,2a,5,5a,7a,7b,7c-Octahydro-5-phenyl-1H-cyclobut[bc]acenaphthylen-1-yl]-2-butenoic acid
Additional Names: (E)-4-(6¢-phenyltetracyclo[5,4,2,03,13,010,12]trideca-4¢,8¢-dien-11¢-yl)but-2-enoic acid
Molecular Formula: C23H24O2
Molecular Weight: 332.44
Percent Composition: C 83.10%, H 7.28%, O 9.63%
Properties: Rosettes from aq ethanol and chloroform/ petr ether, mp 163-165°. uv max (95% ethanol): 252, 258, 262, 265, 269 nm (log e 3.11, 3.08, 3.07, 3.01, 2.97).
Melting point: mp 163-165°
Absorption maximum: uv max (95% ethanol): 252, 258, 262, 265, 269 nm (log e 3.11, 3.08, 3.07, 3.01, 2.97)
Derivative Type: Endiandric Acid C
CAS Registry Number: 76060-34-9
CAS Name: (1R,1aR,3S,3aR,6S,6aS,6bR,7S)-rel-1,1a,2,3,3a,6,6a,6b-Octahydro-1-[(2E,4E)-5-phenyl-2,4-pentadienyl]-3,6-methanocyclobut[cd]indene-7-carboxylic acid
Additional Names: 4-[(E,E)-5¢-phenylpenta-2¢,4¢-dien-1¢-yl]tetracyclo[5,4,0,02,5,03,9]undec-10-ene-8-carboxylic acid
Molecular Formula: C23H24O2
Molecular Weight: 332.44
Percent Composition: C 83.10%, H 7.28%, O 9.63%
Properties: Cryst from ethanol and methanol, mp 125-132° (variable and with dec). uv max (95% ethanol): 222, 228, 236, 280, 288 nm (log e 4.10, 4.05, 3.89, 4.51, 4.53).
Melting point: mp 125-132° (variable and with dec)
Absorption maximum: uv max (95% ethanol): 222, 228, 236, 280, 288 nm (log e 4.10, 4.05, 3.89, 4.51, 4.53)
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