Search results
Results From The WOW.Com Content Network
The Sharpless epoxidation is viable with a large range of primary and secondary alkenic alcohols. Furthermore, with the exception noted above, a given dialkyl tartrate will preferentially add to the same face independent of the substitution on the alkene.To demonstrate the synthetic utility of the Sharpless epoxidation, the Sharpless group created synthetic intermediates of various natural ...
Sh 2-155 is an ionized H II region with ongoing star formation activity, [1] at an estimated distance of 725 parsecs (2400 light-years) from Earth. [2] [3] Sh 2-155 [4] was first noted as a galactic emission nebula in 1959 in the extended second edition of the Sharpless catalogue, [5] being a part of the much larger Cep OB3 Association. [5]
The reaction mechanism of the Sharpless dihydroxylation begins with the formation of the osmium tetroxide – ligand complex (2). A [3+2]-cycloaddition with the alkene (3) gives the cyclic intermediate 4. [9] [10] Basic hydrolysis liberates the diol (5) and the reduced osmate (6).
Sh 2-2, also known as Sharpless 2, is an emission nebula in the constellation of Scorpius. It appears as a mid-range brightness making it difficult to view. It is believed to currently host an X-ray binary star that originated and was ejected from the Scorpius OB1 association. Amateur astronomers can usually see it with a wide field telescope ...
The first wire says "2,2" place the wire where the 2ND column and the 2ND row connects. If the second one says "4,1", place the wire where the 4Th column (on top) and the 1st row connect. Please ...
For cyclic allylic alcohols, greater selectivity is seen when the alcohol is locked in the pseudo equatorial position rather than the pseudo axial position. [2] However, it was found that for metal catalyzed systems such as those based on vanadium, reaction rates were accelerated when the hydroxyl group was in the axial position by a factor of 34.
Sh 2-88A is an HII-type diffuse nebula excited by the type O8 star BD+25°3952. [4] Both neutral and ionized gases in Sh 2-88 are between 150 and 410 solar masses and the dust mass is about 2 to 9 solar masses. The structure been interacting with a HI interstellar bubble shaped by the stellar winds of BD+25°3952 and the blue O8.5II(f) star BD ...
Sh 2-279 (alternatively designated S279 or Sharpless 279) is an HII region and bright nebulae that includes a reflection nebula located in the constellation Orion. It is the northernmost part of the asterism known as Orion's Sword , lying 0.6° north of the Orion Nebula .