title: Kallolide A acetate pyrazoline.
abstract: IN THE CRYSTAL STRUCTURE OF KALLOLIDE A ACETATE PYRAZOLINE [SYSTEMATIC NAME: 7-methyl-16-oxo-4,10-bis-(prop-1-en-2-yl)-17,18-dioxa-14,15-diaza-tetra-cyclo-[9.4.2.1(6,9).0(1,12)]octa-deca-6,8,14-trien-5-yl acetate], C(23)H(28)N(2)O(5), there is a 12-member-ed carbon macrocyclic structure. In addition, there is a tris-ubstituted furan ring, an approximately planar γ-lactone ring [maximum deviation of 0.057 (3) Å] and a pyraz-oline ring, the latter in an envelope conformation. The pyrazoline and the γ-lactone rings are fused in a cis configuration. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions, forming a two-dimensional network parallel to (001). An intra-molecular C-H⋯O hydrogen bond is also present.
authors.affiliation: PO Box 70377, University of Puerto Rico, San Juan, PR 00936-0377,  Puerto Rico.
authors.forename: Idaliz
authors.initials: I
authors.lastname: Rodríguez-Escudero
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Marrero
authors.forename: Abimael D
authors.initials: AD
authors.lastname: Rodríguez