One-pot four-component synthesis of pyrimidyl and pyrazolyl substituted azulenes by glyoxylation–decarbonylative alkynylation–cyclocondensation sequences

• Charlotte F. Gers,
• Julia Rosellen,
• Eugen Merkul and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1173–1181, doi:10.3762/bjoc.7.136

• , such as Friedel–Crafts-type reactions, generally occurs in the 1-position [24]. Interestingly, the azulene motif is also found in terpenoids [27][28]. Guaiazulene (1b) (Scheme 1), a commonly known derivative of azulene (1a), is a naturally occurring sesquiterpene [29]. Guaiazulene (1b) has found entry

• -component approach to heterocyclic derivatives of azulene is well suited for the development of functional chromophores with extended π-conjugation. Selected resonance structures of azulene (1a) and structure of the sesquiterpene guaiazulene (1b). Synthesis of ynones by glyoxylation–decarbonylative

A racemic formal total synthesis of clavukerin A using gold(I)-catalyzed cycloisomerization of 3-methoxy-1,6-enynes as the key strategy

• Jae Youp Cheong and
• Young Ho Rhee

Beilstein J. Org. Chem. 2011, 7, 740–743, doi:10.3762/bjoc.7.84

• sesquiterpene natural products. It was first isolated in 1983, by the group of Kitawara, from the Okinawa soft coral Clavularia koellikeri. The structure of clavukerin A was established by CD spectra and X-ray diffraction [1]. The first total synthesis of clavukerin A was reported by Asaoka in 1991, which was

Synthesis of spiroannulated and 3-arylated 1,2,4-trioxanes from mesitylol and methyl 4-hydroxytiglate by photooxygenation and peroxyacetalization

• Axel G. Griesbeck,
• Lars-Oliver Höinck and
• Jörg M. Neudörfl

Beilstein J. Org. Chem. 2010, 6, No. 61, doi:10.3762/bjoc.6.61

• hydroperoxy alcohol 4 and benzaldehyde derivatives, was investigated by X-ray crystallography. Keywords: ene reaction; peracetalization; peroxides; singlet oxygen; trioxanes; Introduction The antimalaria-active molecule artemisinin (1) is a naturally occurring sesquiterpene peroxide with remarkable